Unloader for compressors or the like



E. A. RIX.

UNLOADER FOR COMPRESSORS OR THE LIKE. APPLICATION FILED [ELIE/I919 1,345,884., Pat nt d July 6, 1920,.

2 SHEEIS-SHEEI I.

, INVENTOR Edward 11.30%

E. A. RIX.

UNLOADEB FOR COMPRESSORS OR THE LIKE.

APPLICATION FILED FEB. 12. 1919.

1,345,884. Pat nt d July 6, 1920.

2 SHEETSSHEE[ 2.

INVENTOR QEtiQl/flfd 11.121324 dla y M ATTORNEYS PATENT orrlce.

EDWARD A. RIX, OF OAKLAND, CALIFORNIA.

UNLOADER FOR COMPRESORS OR THE LIKE.

- Specification of Letters Patent.

Patented July 6,1920.

Application filed February 12. 1919. Serial No. 276,544.

To (ZZZ whom it may concern:

Be it known that I, EDWARD A. RIX, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented new and useful Improvements in Unloaders for Compressors or the like, of which the following is a specification.

This invention relates to an unloader and particularly to an automatic unloader for air or gas compressors, provided with valves of the annular or disk type.

One of the objects of the present invention is to provide a mechanism which is simple in construction, positive and efficient in operation and which will automatically maintain a predetermined air pressure in the discharge line or receiver connected with an air or gas compressor without varying the speed of the compressor or resorting to the use of safety valves or the like.

Another object -of the invention is to accomplish the above results by providing automatic actuated means for opening the inlet valve and holding said valve open, thereby allowing the air to surge in and out of the compressing cylinder while the pressure line or receiver is being unloaded, said means being also adapted to release the inlet valve to permit its normal function the moment pressure in the receiver drops below the predetermined pressure.

4 Further objects will hereinafter appear.

The invention consists of the parts and the construction, combination and arrangement of parts as hereinaftenmore fully described and claimed, having reference to the accompanying drawings, in which Figure 1 is a central vertical section of the upper portion of an air or gas compressor employing annular disk valves.

Fig. 2 is a plan view of theicylinder head showing the upper portion of the same removed. I I

Fig. 3 is a perspective view of the inlet valve.

9 secured in the lower head 2. The valves 6 and 7 are of the annular disk type and are in this instance held against their respective seats by means of a plurality of springs 10 interposed between the respective valves and a cap member 11. Also formed inthe lower head portion'2, exterior of the ports 8 and 8 are a series-of intake ports 12. These ports communicate with an annular passage 13 formed in the head, which in turn communicates with the intake port 4;

formed in the cylinder. The inlet ports 12.

are also normally closed by means of an annular disk valve 14. This valve is interposed between the head and the cylinder the cylinder by means of a passage 17.

In actual operation, when reciprocal movement is transmitted to the piston, it can readily be seen that the downward movement of the piston will create sufficient vacuum in the cylinder to hold the inlet valve 14 away'from its seat, thusuncovering the ports 13 and permitting the air to enter through port 5 and'the annular passage 13. The air thus admitted during the suction stroke is compressed during the re-. turn movement of the piston as the inlet valve instantly closes communication between the cylinder and the inlet passage 13 the moment the suction or vacuum is. relieved. The air compressed discharges through the ports 8 and 8 the moment the pressure is sufficient to overcome the tension of the springs 10. It will therefore escape ,into the central chamber 16 and then through the passage 17 and port 5 which is connected through a pipe 6 with a suitable form of receiver not here shown.

The purpose of the present invention is to provide means for automatically opening the inlet valve 14 and holding the same open the moment a predetermined pressure is obtained in the discharge pipe 6 or the receiver connected therewith. This is accomplished cation with the exhaust port 5 formed in by mounting a series of pistons in the head portion 2, as shown at 17 there being three of said pistons employed in the present instance, see Fig. 2. These pistons are reciprocally mounted in cylinder chambers formed for their reception and ezich piston is provided with a pin projection 18 normally engaging the inlet valve 14; when this is closed. Means are provided for depressing said pistons in unison to open the inlet valve 14 and to retain said valve open the moment a predetermined pressure is obtained in the discharge pipe .6 or the receiver connected therewith. The means referred to is directly actuated by said air under pressure and the pistons 17 are also actuated by said air under pressure.

Mounted on the upper portion of the cylinder head is a valve 19. This valve is in is in reality nothing more or less than a diaphragm actuated valve which is opened and a closed by air under pressure admitted thereto. The present form of'valve comprises a casing 20 in which is mounted a diaphragm 21. Formed below the diaphragm is a chamber 22 to which air under pressure is admitted through a pipe 23. This pipe is connected with the discharge pipe 5 and.the diaphragm 21 is therefore actuated by the air pressure in the discharge pipe or the receiver connected therewith. Mounted above the diaphragm is a plunger 24: and a spring 25, the tension of which may be regulated by means of an adj u'sting screw 26. Mounted below the diaphragm is a piston valve 27 in which is formed an air passage 28. This valve is provided with a head on its upper end which engages the diaphragm and a spring 29 interposed between the head and a seat formed for the Valve normally maintains thehead in engagement with the diaphragm. Slidably mounted in the casing below the piston valve and adapted to engage the same, is a disk valve 30 which is held in engagement with the piston valve by means of a spring 31. This valve serves the function of admitting the air under pressure contained in chamber 22 to a vertical passage 32 which communicates with a pas-' sage 33 formed in the upper portion of the head 2 and lateral passages 34 which com-v municate with the respective pistons 17 The disk valve also serves the function of exhausting the air delivered to the passages 32 and 33 and the cylinders containing the pistons 17. v Y

The operation will be as follows: With the compressor operating it can readily be seen thatv the air constantly discharged by the same will gradually produce a greater and greater pressure in the discharge pipe 6 and the'receiver connected therewith unless. the air thus delivered is permitted to.

municating with the same reach their full: charge. If it is desired to maintain a maximum pressure of, for instance, eighty pounds in the receiver and the pipes communicating therewith, it is accomplished in the present instance by adjusting the tension of the spring 25 in the pilot valve 19 so that the diaphragm may raise the moment a pressure of eightly pounds is obtained. Upward movement of the' diaphragm permits the piston valve 28 and the disk valve 30 to rise inunison, due to the action of the springs 29 and 31. The disk valve is perforated as at 30 and it serves the function in this instance of first closing a pair of exhaust ports cation between the passages 28 and 32 through the perforations 30. The air under pressure admitted through pipe 23 and chamber '22 will thus pass downwardly through the passage 32 and the passage 33 and will finally pass through the lateral passages 34 into the cylinder chambers containing the piston 17. The pistons will thus move in a downward direction and the pins 18 carried thereby will engage the inlet valve and depress the same or move it away from its seat and uncover the inlet ports 12. Air admitted through the ports 12 during the suction stroke of the piston will thus also escape through the same ports during the reverse movement of the piston. In other words, a surging or'breathing action will take place as long as the pressure in the receiver and the connected pipe lines is mainvalve 30, in this manner opening the exmunicating therewith. The tension of the" springs 15 will then raise the pistons to normal position and permit the inlet valve to engage its seat. The valve is therefore free to perform its normalfunction and air will again discharge through the exhaust ports 8 and 8 and pass into the discharge pipe 5 and the receiver connected therewith.

From the foregoing" description it will readily be understood that the annular disk valves are extremely light and flexible and must have pressure applied thereto at more than one point in order to push them open and hold. them in that position. readily accomplished in the present instance as the invention comprises the placing of a series of small pistons directly over thesurface of the annular valves at equi-distant points, the small cylinders holding these pistons being all connected with the discharged air under pressure, through the pilot valve and all operating at the same instant to push the inlet valve open when actuated by This is there is ample space in the compressor head to introduce as many may be required, three being employed for a valve 7 inches in diameter, four for a ten-inch valve, etc.

lVhile a pilot valveof specific construction is here shown, I wish it understood that any other form of valve suitable for the pur-' pose may be employed. Similarly, that the materials and finish of theseveral parts comprising the invention and the arrangeand ment of the same may be varied to suit various applications and installations.

Having thus described my invention, what I claim and desire to secure by Letters Patent is r 1. In a fluid compressor the combination with an inlet valve of annular ring shaped form, and an exhaust valve, of a discharge pipe communicating with the exhaust valve and a plurality of plungers engageable with the inlet valve actuated by the pressure in the discharge pipe for opening the inlet valve and holding it open the moment a predetermined pressure is obtained in the discharge pipe.

2. In a fluid compressor the combination with an inlet valve of annular ring shaped form and an exhaust valve, of a discharge pipe communicating with the exhaust valve,

a plurality oficylinders positioned above the inlet valve, a piston in each cylinder, means carried by each piston engageable with the inlet valve, and means for automatically admitting fluid under pressure from the discharge pipeto the cylinders to depress the piston and to open and hold the inlet valve open the moment a predetermined pressure is obtained in the discharge pipe.

4. In a fluid compressor the combination with an inlet valve of annular ring shaped form andan exhaust valve, of a discharge pipe communicating with the exhaust valve, a plurality of cylinders positioned above the inlet valve, a piston in each cylinder, means carried by each piston engageable with the inlet valve, and means for automaticallyadmitting fluid under pressure from the discharge pipe to the cylinders to depress the pistons and to open and hold the inlet a plurality of pneumatic actuated valve open the moment a predetermined pressure is obtained in the discharge pipe,

said means also adapted to automatically ex haust the air admitted to the cylinders and to release the inlet valve to permit it to resume its normal function the moment the pressure in the discharge pipe drops below the predetermined pressure.

5'. In a fluid compressor the combination with an inlet valve of annular ring shaped form and an exhaust valve, of a discharge pipe communicating with the exhaust valve, pneumatically actuated plungers adapted to engage the inlet valve to open the same and hold it open the moment a predetermined pressure is obtained 1n the discharge pipe,

and a pressure actuated valve connected with the" discharge pipe adapted to automatically admit fluid under pressure from the discharge pipe to operate said pneumatic actuated plungers.

6. In a fluid compressor the combination with an inlet valve of annular ring shaped form and an exhaust valve, of a discharge pipe communicating with the exhaust valve, a plurality of cylinders positioned adjacent the inlet valve, a piston in each cylinder,

means carried by each piston engageable with the inlet valve, and a pressure actuated valve connected with the discharge pipe adapted to automatically admit fluid under pressure to the piston-cylinders to depress the pistons and open and hold the inlet valve open the moment a predetermined pressure a is obtained in the discharge pipe, said pres- I sure actuated valve also adapted to exhaust the fluid admitted to the piston cylinders to permit the inlet valve to resume its normal function.

7. In a fluid compressor the combination with a cylinder, of a piston reciprocally mounted in said cylinder, a head member on the cylinder, an inlet and an exhaust valve in said head, a discharge pipe communicating with the exhaust valve, a plurality of cylinder chambers formed in the head ad jacent the inlet .valve, a piston in each of said cylinders, means carried by each piston engageable with the inlet valve, and automatic means actuated by the fluid pressure .in the discharge pipe for admittin fluid under pressure to the cylinders o depress the pistons and to open and hold the inlet valve open the moment a predetermined pressure is obtained in the discharge pipe, saidmeans also adapted to automatically exhaust thefiuid admitted to the cylinders and to release the inlet valve to permit it to resume its normal function the moment the pressure in the discharge pipe drops below the predetermined pressure.

means carried by each piston engageable with the inlet valve, a fluid inlet passage formed in the head communicating with the respective piston cylinders, a pressure actuated valve connected with said passage mined pressure.

adapted-to admit fluid under pressure from the discharge pipe to depress the pistons and open and hold the inlet valve open the moment a predetermined pressure is obtained in the discharge pipe, said pressure actuated valve also adapted to exhaust the fluid admitted to the piston cylinders to permit the inlet valve to resume its normal function the moments the pressure in the discharge pipe drops below the predeter- 9. In a fluid compressor, the combination with a cylinder, of a piston reciprocally mounted in said cylinder, a cylinder head on the cylinder, an inlet valve of annular ring shaped form mounted in said head, an exhaust valve also mounted in the head,

a discharge pipe communicating with the each cylinder, a plunger extension on each piston engageable with the inlet Valve, a spring surrounding each plunger extension adapted to normally hold the pistons and plungers in elevated position out of contact with the inlet valve, and a pressure actuated valve connected with the discharge pipe and with the annular fluid receiving passage in the cylinder head adapted to automatically admit fluid under pressure from the discharge pipe to depress the pistons and open and hold the inlet valve open the moment a predetermined pressure is obtained in the discharge pipe, said pressure actuated valve also adapted to automatically exhaust the fluid admitted to the annular fluid passage and the piston cylinders to per- 5 mit the springs to raise the plungers and pistons out of engagement with the inlet valve and to permit the inlet valve to assume its normal function the moment the pressure in the discharge pipe drops below the predetermined pressure.

10. In a fluid compressor, the combination with a cylinder of a piston reciprocally mounted in said cylinder, a cylinder head on the cylinder, an inlet valve of annular ring shaped form mounted in the head, an exhaust valve also mountedin'the head, a discharge pipe communicating with the exhaust valve, an annular fluid receiving passage formed in the upper surface of the cylinder head, a plurality of cylinder chambers also formed in the cylinder head and in communication with said annular fluid receiving passage, a piston member refluid receiving passage and the cylinder chambers formed in the cylinder head, an opening in the cover communicating with the annular fluid receiving passage and the cylinder chambers, and an automatic pressure actuated val've communicating with said opening in the cover and also communicating with the discharge pipe, said valve adapted to admit fluid under pressure from the discharge pipe to depress the pistons and plungers attached thereto to open and hold the inlet valve open the moment a predetermined pressure is obtained in the discharge pipe, said pressure actuated, valve also adapted to exhaust the fluid admitted to the annular fluid receiving passage and the communicating cylinder chambers to permit the pistons and plungers to be raised by the springs and thereby allow the inlet valve to assume its normal function the moment I the pressure in the discharge pipe drops,

below the predetermined pressure.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

' EDWARD AQRIX,

Witnesses:

JOHN H. HERRING, W. .W. HEALEY. 

